Question

I am raising exceptions in two different places in my Python code:

holeCards = input('Select a hand to play: ') try:     if len(holeCards) != 4:         raise ValueError(holeCards + ' does not represent a valid hand.') 

AND (edited to correct raising code)

def __init__(self, card):   [...]    if self.cardFace == -1 or self.cardSuit == -1:     raise ValueError(card, 'is not a known card.') 

For some reason, the first outputs a concatenated string like I expected:

ERROR: Amsterdam does not represent a valid hand. 

But, the second outputs some weird hybrid of set and string:

ERROR: ('Kr', 'is not a known card.') 

Why is the ‘+’ operator behaving differently in these two cases?

Edit: The call to init looks like this:

  card1 = PokerCard(cardsStr[0:2])   card2 = PokerCard(cardsStr[2:4]) 

Answer 1

‘card’ probably represents a tuple containing the string ‘Kr.’ When you use the + operator on a tuple, you create a new tuple with the extra item added.

edit: nope, I’m wrong. Adding a string to a tuple:

>> ('Kr',) + 'foo' 

generates an error:

TypeError: can only concatenate tuple (not 'str') to tuple 

It would probably be helpful to determine the type of ‘card.’ Do you know what type it is? If not, try putting in a print statement like:

if len(card) != 2:     print type(card)     raise ValueError(card + ' is not a known card.')